In order to make reliable A/B comparison tests between 2 headphone amplifiers, the PSB2-1 must be connected between your 2 headphone amplifiers and your headphone as shown in the diagram below. All connections are done using regular 1/4″ jacks.

Connect the headphone output jacks of the 2 amplifiers respectively to the A and B jack INPUTS located on the back of the PSB2-1, using [stereo 1/4” jack plug – stereo 1/4” jack plug] cables (High quality Klotz cables, with Amphenol Nickel plated 1/4″ plugs can be provided optionally, or make your own cables)

Connect your headphones to the 1/4” OUTPUT jack on the front of the PSB2-1.

Use the toggle switch to switch between the A and B amplifiers signals. It is very important that you match the levels of the 2 headphone amplifiers carefully, in order to have a reliable comparison and A/B test.

The sonic differences (if they exist) between the connected headphone amplifiers will be easily apparent as we can switch from one to the other instantly using the toggle switch, without any other distraction (no need to stop listening and pull and plug cables…, just switch between A and B with the toggle switch…)

Only high quality components with internal silver plated contacts are used in the PSB2-1 (toggle switch and all 1/4” jack connectors).